\[ a y(x)+(b+x) y'(x)+x y''(x)=0 \] ✓ Mathematica : cpu = 0.023153 (sec), leaf count = 40
\[\left \{\left \{y(x)\to c_1 e^{-x} U(b-a,b,x)+c_2 e^{-x} L_{a-b}^{b-1}(x)\right \}\right \}\] ✓ Maple : cpu = 0.204 (sec), leaf count = 30
\[\{y \left (x \right ) = \left (c_{1} \KummerM \left (-a +b , b , x\right )+c_{2} \KummerU \left (-a +b , b , x\right )\right ) {\mathrm e}^{-x}\}\]